Final answer:
Jocasta's initial relief over Polybus' death turns to despair as she realizes Oedipus is her son, not her happiness. Her reaction ultimately leads to her, making the statement that she is happy false.
Step-by-step explanation:
When considering if Jocasta is happy to hear the news of Polybus' death, it is crucial to understand her role and structure of events in the Greek tragedy 'Oedipus Rex'. Jocasta initially believes that with the death of Polybus, one part of the dreadful prophecy — that Oedipus would kill his father — is proven wrong, which would seemingly be reason for relief. However, the truth that soon unfolds is that Polybus was not Oedipus' biological father.
Jocasta finds out that her husband is actually her son, and this horrifying revelation leads to her tragic. Therefore, stating that Jocasta is happy about Polybus' death is false. The initial relief is quickly overshadowed by the unfolding of tragic events leading to her demise, revealing that her emotions were far more complex and ultimately ended in despair.